class CNode (object):
	__slots__=['__data',  '__left', '__right']
	def __init__( self, data, left, right):
		self.__data = data
		self.__left = left
		self.__right = right
	def __str__(self):
		return str(self.__data)
	def getData(self):
		return self.__data
	def getLeft(self):
		return self.__left
	def getRight(self):
		return self.__right
	def setData(self, data):
		self.__data=data
	def setLeft(self, data):
		self.__left = data
	def setRight(self, data):
		self.__right = data